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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

[en] INTEGRATION POTENTIAL OF MICROALGAE BIODIESEL TO SURGARCANE-ETHANOL INDUSTRY IN BRAZIL: HERMODYNAMIC AND ENVIRONMENTAL ANALYSES / [pt] POTENCIAL DE INTEGRAÇÃO DA PRODUÇÃO DE BIODIESEL DERIVADO DE MICROALGAS À INDÚSTRIA SUCROALCOOLEIRA NO BRASIL: ANÁLISE TERMODINÂMICA E AMBIENTAL

SERGIO LUIZ PINTO CASTINEIRAS FILHO 19 June 2020 (has links)
[pt] O objetivo dessa dissertação é apresentar a simulação de processos, no software Aspen HYSYS (marca registrada) v8.8, de uma planta de etanol derivado de cana-de-açúcar, abrangendo o sistema de cogeração e hidrólise enzimática aplicáveis ao bagaço, e associada a uma planta de cultivo de microalgas para produção de biodiesel de terceira geração. Adicionalmente, foram avaliados, por planejamento composto central 32, os efeitos de duas variáveis – designação de bagaço para hidrólise enzimática (x1) e de etanol para desidratação (x2) - sobre parâmetros de performance energéticos e ambientais restritos à planta, e negligenciando-se contribuições do âmbito rural. Em um cenário similar à realidade brasileira - coordenadas (0, 50 por cento) -, observou-se que a integração proporciona uma quantidade significativa de biodiesel (26,6 kg.t-1 de cana), em termos energéticos, além da oferta de etanol (62,2 kg.t-1 de cana). Nesse cenário, a demanda energética da seção de microalgas-biodiesel demonstrou-se semelhante à da planta de etanol. Os modelos produzidos demonstram-se robustos e precisos (R2 superiores a 0,998). As avaliações estatísticas indicaram que x1 afeta quadraticamente as respostas, e x2 promove efeitos nulos ou brandos. Destaca-se valores de NER - razão entre contribuições energéticas de produtos e de insumos do sistema -entre 0,763 e 0,904, próximos a 1; e valores de FER - razão entre as contribuições energéticas dos produtos e das participações fósseis de insumos - entre 4,33 e 10,88, acima 3, o que configura caráter renovável ao sistema. Dentre as otimizações de respostas, encontrou-se a coordenada (92 por cento, 0) para eficiência exergética global. Por fim, a associação das plantas de etanol e de biodiesel forneceu resultados promissores para as eficiências energéticas, razão entre oferta de energia total e consumo de energia fóssil, e incremento de eficiência exergética da planta de etanol original. / [en] The objective of this dissertation is to present a simulation in the software Aspen HYSYS (Registered trademark) v8.8 of a sugarcane-ethanol plant covering a cogeneration and an enzymatic hydrolysis system, applicable to bagasse final use, and associated to a microalgae-cultive plant for the production of third-generation biodiesel through transesterification route. Additionally, the effects of two variables - designation of bagasse to enzymatic hydrolysis (x1) and of ethanol to dehydration (x2) - were statistically evaluated by 3(2) central composite design over energetic and environmental performance parameters restricted to the plant s scope and being neglected contributions of the rural area. In a base scenario similar to Brazilian’s reality – coordinates (0, 50 per cent) –, it was observed that the integration provides a quantity of biodiesel (26.6 kg.t-1 of sugarcane) energetically significant, besides the supply of ethanol (62.2 kg.t-1 of sugarcane). In this case, the energetic demand of the microalgae-biodiesel section pointed to be similar the conventional ethanol plant consumption. The adjusted models were robust and precise (R2 higher than 0.998). The statistical assessments pointed that x1 affects quadratically the answers and x2 promotes null or mild effects. Stands out NER values - ratio between energetic contribution of products and inputs of the system - between 0.763 and 0.904, which were close to 1, and FER values - ratio between energetic contributions of products and fossil share of inputs - between 4.33 and 10.88 that were higher than the 3, which configured renewability to the system. Among the optimization of the answers, it was found the coordinate (92 per cent, 0) for the global exergetic efficiency. Finally, the association of the ethanol and biodiesel plants provided promising results for energetic efficiency, ratio between total delivered energy and demanded fossil energy, and increase in exergetic efficiency of the original ethanol plant.
62

A systematic approach for major renovation of residential buildings

Liu, Linn January 2017 (has links)
In Sweden, buildings are responsible for about 40 % of total energy use and about 10 % of total CO2 emissions Today more than 60 % of existing Swedish residential buildings are over 40 years old and are in need of major renovation. In addition, 15 % of all multi-family buildings and 27 % of all single-family houses were built before 1945. The increased energy use and threat from CO2 emissions of the building sector create a need for energy efficiency. The important role that renovation of residential buildings will play in reducing the total energy used by the Swedish building sector as well as in reducing primary energy use and CO2 emissions on both the national and global levels has been the impetus for the studies included in this thesis. The aim of the current research is to develop a methodology from a system perspective which can be used to analyze the energy use, optimal life cycle cost (LCC), energy efficiency measure (EEM) package, indoor environment, CO2 emissions, and primary energy use of a building or a community during major renovation. The developed methodology accomplished at three different levels, i.e. building level, cluster level and district level. The methodology considers both energy efficiency and economic viability during building renovation and will also play an important role in overall urban planning. The studied buildings include both non-listed and listed residential buildings and the tools used include building energy simulation (BES), survey, technical measurements, LCC optimization and building categorization. The results show that the combination of BES, technical measurements and surveys provides a holistic approach for evaluation of energy use and indoor environment of the studied residential buildings. The results from the current study also show that the 2020 energy target, i.e., reduction of energy use by 20 %, for the building sector can be achieved by all the studied building types and that the total LCC of these buildings are below the cost-optimal point. In comparison, the 2050 energy target, i.e., reduction of energy use by 50 %, for the building sector may be achieved by the non-listed buildings, but when the constraints relevant to listed buildings are added the cost-optimality changes as some EEMs in direct conflict with the building’s heritage value may not be implemented. The investigation of primary energy use and CO2 emissions by the residential buildings show that the higher the energy saving, the lower the primary energy use becomes, and vice versa. With the same energy saving, the heating system with higher primary energy factor results in higher primary energy use. From a CO2 emissions point of view, EEM packages proposed to help buildings connected to a CHP based district heating system, to reduce the energy use or LCC are not consistently effective. Since these EEM packages will reduce district heating demand, the electricity produced in the CHP plant will also decrease. When the biomass is considered a limited resource, measures such as investment in a biofuel boiler are not favourable from the CO2 emissions point of view. The current study has also shown that combining building categorization method and LCC optimization method will help the community to reduce its energy use, primary energy use and CO2 emissions in a systematic and strategic way. / I Sverige, står byggnadssektorn för cirka 40 % av den totala energianvändningen och cirka 10 % av CO2-utsläppen. Idag är mer än 60 % av befintliga svenska bostäder över 40 år gamla och i stort behov av renovering. Dessutom är 15 % av alla flerbostadshus och 27 % av alla småhus byggda före 1945. Den ökade energianvändningen och hotet från CO2-utsläpp från byggsektorn skapar ett behov av energieffektivisering. Grunden för studierna i denna avhandling är den stora betydelse som renoveringen av bostäder har, såväl för att kunna minska den totala energianvändningen som den primärenergianvändningen och CO2-utsläppen på både nationell och global nivå. Syftet med denna forskning är att utveckla en metodik ur ett systematiskt perspektiv som kan användas för att analysera energianvändning, finna optimal livscykelkostnad (LCC), skapa energieffektiviseringsåtgärdspaket, undersöka inomhusmiljöer, beräkna CO2-utsläpp och primärenergianvändning i en byggnad eller ett samhälle vid omfattande renovering. Den utvecklade metodiken som har använts i de aktuella studierna är på tre olika nivåer: byggnadsnivå, klusternivå och stadsdelsnivå. Metodiken avser både energieffektivitet och ekonomisk lönsamhet vid renovering av byggnader och kommer också att spela en viktig roll i den övergripande stadsplaneringen. De studerande byggnaderna i denna avhandling innefattar både historiska och icke-historiska bostäder. De använda verktygen inkluderar building energy simulering (BES), enkätundersökning, tekniska mätningar, LCC-optimering och byggnadskategorisering. Resultaten visar att kombinationen av BES, tekniska mätningar och enkätundersökning ger en god helhetsbild för utvärdering av energianvändning och inomhusmiljö av den studerade byggnaden. Resultaten från den aktuella studien visar också att 2020-energimålet, d.v.s. en minskning av energianvändningen med 20 % till 2020 av byggsektorn, kan uppnås i alla undersökta byggnader och att den totala LCC av dessa byggnader ligger under den kostnadsoptimala punkten. I jämförelse, kan 2050-energimålet, d.v.s. en minskning av energianvändningen med 50 % till 2050, kan uppnås i icke-historiska byggnader, men med hänsyn tagen till begränsningarna för historiska byggnader, ändras de kostnadsoptimala lösningarna, eftersom vissa energieffektiviseringsåtgärder är i direkt konflikt med byggnadens kulturhistoriska värde och därför inte kan genomföras. Undersökningen av primärenergianvändning och CO2-utsläpp i de studerade byggnaderna visar, att ju högre energibesparingen är, desto lägre blir primärenergianvändningen, och vise versa. Med lika mycket energibesparing, resulterar värmesystemet med högre primärenergifaktor i högre primärenergianvändning. Sett från CO2-utsläppssynvinkel, är de energieffektiviseringsåtgärdspaket, som kan hjälpa byggnader anslutna till ett kraftvärmebaserat fjärrvärmesystem att minska energianvändningen eller LCC, inte effektiva, eftersom dessa åtgärdspaket kommer att minska fjärrvärmeanvändningen. Detta leder till att mängden producerad el i ett kraftvärmeverk också kommer att minskas. När biobränsle betraktas som en begränsad resurs, är åtgärder som investering i en biobränslepanna inte energieffektiva från en CO2-utsläppssynvikel. Den aktuella studien visar också att kombinationen av byggnadskategorisering och LCC-optimering kommer att hjälpa byggnadssektorn att minska sin energianvändning, primärenergianvändning och CO2-utsläpp på ett systematiskt och strategiskt sätt.
63

Projection of Municipal and Industrial Solid Waste Generation in Chinese Metropolises with Consumption and Regional Economic Models / 消費と地域経済のモデルに基づいた中国大都市の一般及び産業廃棄物の発生量推計 / ショウヒ ト チイキ ケイザイ ノ モデル ニ モトズイタ チュウゴク ダイトシ ノ イッパン オヨビ サンギョウ ハイキブツ ノ ハッセイリョウ スイケイ

YANG, Jinmei 24 September 2009 (has links)
The increasing volume of solid waste (SW), not only arising from household (Municipal SW, MSW) but also from industrial process (Industrial SW, ISW), has become a serious issue in Chinese metropolises with the economic growth, urbanization, industrialization, and increasing affluence. Growth of industry leads to the expansion of population, while the augment of demand by increasing population stimulates the industrial growth in turn, thereby increasing not only ISW generation, but also MSW generation. Therefore, in order to solve the waste problem for the construction of sustainable waste management system in a city, it is necessary to consider these two types of waste together, in which, the emphasis should be focused on waste reduction from the source. The starting point in adopting this should be a good understanding of the upstream flow of waste and accurate knowledge of the volume and composition of waste that will be generated in the future. However, due to deficient historical records and complex production process, the effective attempts at forecasting SW generation are far from enough, especially for ISW by waste category. A common approach which is based on the limited waste statistics and can be easily popularized into Chinese countries is thus urgent. This paper, therefore, attempts the construction of a systematic approach to make projections of SW generation by waste category from the following issues: (1) to develop household consumer behaviour model taking into account lifestyle of residents and project the demand of private consumption in the future; (2) to quantitatively investigate and project MSW generation fully considering the change in consumer behaviour and waste management policies; (3) to effectively evaluate the present and future industrial structure and their contributions to ISW generation among industries; (4) to carry out a scenario analysis of calculating CO2 emissions in different waste treatment options based on the projected waste quantity and composition in 2015. The approach is applied on a city level as the basic administrative unit of SW management in China. The entire framework comprises four modules-regional macro-economic module, MSW generation module, ISW generation module, and waste treatment module. Further, the study of consumption pattern conducted from the consumer behaviour model in MSW module is a prerequisite for industrial restructuring caused by change in consumption demand in ISW module. Moreover, the regional macro-economic module is to provide a means for economic structural analysis and economic forecasting, considering the influence of national GDP and socioeconomic indicators including world trade. It is found out that the regional model fits the historical records reasonably well and provides an acceptable reproduction. In the MSW generation module for estimating and projecting MSW generation, firstly the per capita total household consumption expenditure is estimated by using total consumption expenditure model; then, household consumption pattern is estimated using an extension of the linear expenditure system (LES); thereafter, MSW generation by composition is quantitatively expressed in terms of the expenditure for consumption category and waste management policies by using ordinary least squares (OLS). Then, five Chinese cities with distinct economic levels are presented by applying the module to determine the waste generation features in different regions. The research findings clearly indicate that 1) the number of variables affecting consumer behaviour in Chinese cities is not one but the integrations of a series of indicators. Aside from Shanghai, saving rate towards consumption (SAV) and natural growth rate (NAGR) are currently the two common factors. However, in Shanghai, consumer behaviour is strongly influenced by SAV and the average number of persons per household (ANPH). 2) The MSW generation model quantitatively demonstrates the linear conversion process from consumption to corresponding waste generation in all cities. For example, education and consumption of food-as the form of consumption expenditure in this research-is the source of generation of food, plastic and paper waste. Further, glass and metal waste is estimated by food expenditure in all cities. 3) Total MSW generation per unit consumption is 0.198~0.225 kg/RMB with an average value of 0.213 kg/RMB. 4) All the waste management policies analyzed in the research will provide feasible experiences or valuable lessons to other Chinese cities. 5) Volume of per capita MSW generated in 2020 will be 1.24-2.18 folds compared to that in 2008 in each city if there were no effective policies implemented advancing to diminishing waste generation. Then, for the forecasting of ISW generation of each waste category by industry, the ISW module is developed, linking three principal models-regional macro-economic model, regional input-output (IO) analysis, and ISW generation model. The approach investigates the influence of industrial restructuring on ISW generation, based on the study of consumption patterns, export composition figures and change in ISW generation coefficient. The principal priorities in the case study on Shanghai are as follows: 1) the approach provides an idea for a way to quantitatively analyze industrial restructuring by adjusting the converter that, in turn, helps assess the impact of these changes on sectoral output. 2) A sensitivity analysis describes that per yuan of increase in consumption on FOOD, CLSH, FUNI, EDUC, TRAN, HLTH and RESI induces to an average increase of 76.41, 76.16, 82.28, 106.54, 93.89, 148.30 and 292.58 g total ISW, respectively. 3) It is verified that ISW generation not only arises from economic growth but also from the onset of industrial restructuring. The unit ISW generation per gross output reduces from 0.16 to 0.14 tons/10 000 RMB as we move from 2002 to 2020. 4) It is investigated that the total volume of ISW generated in 2010, 2015 and 2020 will be 2.07, 2.83 and 4.12 times that of the 2002 levels. The total SW generation of Shanghai in 2020 will be 4.06 times of that in 2002. 5) However, if considering scenario analysis of adjusting ISW generation coefficient, the total SW generation is 1.93 times compared to 2002 and ISW is 2.18 times of MSW generation. 6) Based on our results, the industrial sectors making the biggest contribution to the production of each type of ISW can each be separately identified. Therefore, constraining specific industries or penetrating them with selective technological changes will be useful attempts on the way to meeting the objectives of overall waste reduction. Finally, in the waste treatment module, the greenhouse gas (GHG) emissions emitting from the treatment and disposal of waste, including landfill site, waste-to-energy incineration and composting are calculated, respectively. Further, based on the projection of waste quantity and composition of Shanghai in 2015, a scenario analysis is carried out as well concerning the GHG emissions from alternative treatment options. The results confirm that composting and recycling of waste before the treatment are effective attempts at reducing GHG emissions in Shanghai. Further, scenario designed as the integrated waste treatment system makes the biggest reduction of GHG emissions, as 34% as compared to current treatment options with energy recovery. In a word, this research develops the entire systematic approach investigating the upstream flow of waste generation from the viewpoint of economic growth, change in socioeconomic indicators and constitution of waste management policies, and makes a reasonable attempt at projecting SW generation of each type of waste category. Based on the results, it is suggested that for the waste reduction to promote sustainable society, government interventions including promoting green consumption, reducing extra consumption, et al. and waste policies such as increasing recycling and penetrating technological innovation in specific industries will be effective. Further, based on the forecasts of SW generation, the recycling and appropriate treatment of waste generating from municipal and industrial process can be examined from the long view. From the relationship between ISW and MSW generation, the development of industry will promote the growth of service industry and induce greater generation of recyclable items. While the recycling of these items before the waste treatment is essential for effectively reducing GHG emissions which contribute to global warming. In addition, the systematic model can be easily popularized into other Chinese cities even other Asian developing cities, thereby possibly promoting the sustainable waste management of China and Asian countries. / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14928号 / 工博第3155号 / 新制||工||1473(附属図書館) / 27366 / UT51-2009-M842 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 松岡 譲, 教授 森澤 眞輔, 准教授 倉田 学児 / 学位規則第4条第1項該当
64

Použitelnost ložového popele z vitrifikovaného lignitového uhlí v kompozitních cementech. / Suitability of vitrified lignite bottom ash for composite cements.

Bayer, Petr January 2014 (has links)
Předložená magisterská práce se zabývá možným použitím vitrifikovaného lignitového lóžového popele jako náhrada slinku v kompozitních cementech. Byly zkoumány vlivy přidaného vitrifikovaného lóžového popele, jeho jemnosti, alkalických roztoků a jejich koncentrací. Byly připraveny kompozitní cementy v souladu s normou DIN EN 197 – 1. V těchto cementech bylo nahrazeno 30 % slinku vitrifikovaným lóžovým popelem. Konkrétně byly připraveny kompozitní cementy s vitrifikovaným lóžovým popelem o jemnosti 5549 cm2/g a 8397 cm2/g. Dále byly přidány alkalické roztoky hydroxidů a síranů vždy o dvou různých koncentracích, za účelem stimulace pucolánové a/nebo geopolymerní reakce. Mechanické vlastnosti připravených vzorků byly charakterizovány mechanickým testováním na prizmách s rozměry 40×40×160 mm, jak je specifikováno v normě DIN EN 196 – 1. Byla provedena nedestruktivní měření dynamického elastického modulu a destruktivní testovaní na pevnosti v tlaku a v ohybu. Distribuce velikosti částic a chemická analýza vstupních materiálů byla vykonána pomocí laserové granulometrie a rentgenové fluorescence. U zatvrdlých kompozitů bylo dále zkoumáno po 2 a 28 dnech hydratace fázové složení s využitím metody rentgenové difrakce a mikrostruktura s využitím skenovací elektronové mikroskopie. Výsledky ukázaly, že mechanické vlastnosti jsou nezávislé na množství přidaných alkálií stejně jako na jemnosti přidaného vitrifikovaného lóžového popele. Nicméně, znatelně nižší mechanické pevnosti byly pozorovány pro vzorky, které byly aktivovány hydroxidy, pravděpodobně kvůli brzké tvorbě silikátového hydrogelu. Vzorky aktivované sírany nedosáhly pevností jako referenční malta.

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